Impact of aortic valve calcification severity and impaired left ventricular function on 3-year results of patients undergoing transcatheter aortic valve replacement.

OBJECTIVES: To evaluate clinical pre-interventional predictors of 3-year outcome and mortality in high-risk patients with severe aortic valve stenosis treated with transcatheter aortic valve implantation (TAVI). METHODS: Among 367 patients included in the Aachen TAVI registry, 76 patients with baseline dual-source computed tomography (DSCT) for the quantification of aortic valve calcification (AVC) and a 3-year follow-up were identified. RESULTS: Survival at 30 days was 91 %, and it was 75 %, 66 % and 64 % at 1, 2 years and 3 years, respectively. Non-survivors at 3 years showed a significantly higher Agatston AVC score (2,854 ± 1,651) than survivors (1,854 ± 961, P = 0.007). Multivariate analysis including age, logistic EuroScore, glomerular filtration rate, Agatston AVC score, ejection fraction < 40 %, NYHA class, baseline medication, chronic lung disease and aortic regurgitation revealed that only the Agatston AVC score (P = 0.03) and impaired left ventricular function (P = 0.001) was significantly associated with mortality. Patients with Agatston AVC scores >2,000 had a significantly lower 3-year survival rate compared with patients with scores <2,000 (47 % vs 79 %, P = 0.004). CONCLUSIONS: In patients referred for TAVI, aortic valve calcification severity and impaired left ventricular function may serve as a predictor of long-term mortality. Therefore, AVC scores easily determined from pre-procedural CT datasets may be used for patient risk stratification.

Sclerostin as a potential novel biomarker for aortic valve calcification: an in-vivo and ex-vivo study.

BACKGROUND AND AIM OF THE STUDY: Sclerostin is a key negative regulator of bone formation. It was hypothesized that sclerostin might also play a potential role in the development of aortic valve calcification (AVC). The study aim was to evaluate serum sclerostin levels in patients with different degrees of AVC compared to a healthy control group, and to investigate local sclerostin expression in explanted calcified and non-calcified aortic valves. METHODS: A prospective cross-sectional study was performed in 115 patients (mean age 74 +/- 7 years) with echocardiographically proven AVC. Sclerostin serum levels were measured using ELISA and compared to values obtained from a healthy control population. For quantification of AVC, all patients of the study cohort underwent non-contrast-enhanced dual-source computed tomography (DSCT). Immunohistochemistry (IHC) staining for sclerostin and mRNA sclerostin expression was analyzed in 10 calcified aortic valves and 10 non-calcified age-matched control valves. RESULTS: Patients with AVC showed significantly higher sclerostin serum levels as compared to healthy controls (0.94 +/- 0.45 versus 0.58 +/- 0.26 ng/ml, p < 0.001). A significant correlation between sclerostin serum levels and Agatston AVC scores as assessed by DSCT was observed (r = 0.62, p < 0.001) in the study cohort. IHC revealed positive sclerostin staining in nine calcified valves, in contrast to negative staining for sclerostin in all non-calcified valves. Quantitative real-time PCR confirmed the increased sclerostin expression on mRNA level, with a significant up-regulation of sclerostin mRNA (fold change 150 +/- 52, p < 0.001) expression being shown in calcified aortic valves compared to non-calcified control valves. Co-staining experiments revealed that sclerostin-expressing cells co-express the major osteogenic transcription factor Runx2 and the extracellular matrix protein osteocalcin. CONCLUSION: Patients with AVC showed increased sclerostin serum levels compared to a healthy reference population, and it was revealed that the severity of AVC may be linked to increased sclerostin serum levels. Moreover, the PCR and staining data demonstrated an increased sclerostin expression in parallel to prototypic markers of osteogenic transdifferentiation, indicating a role of sclerostin in the valvular calcification process.

Relationship between sclerostin and cardiovascular calcification in hemodialysis patients: a cross-sectional study.

BACKGROUND: Sclerostin is a Wnt pathway antagonist regulating osteoblast activity and bone turnover. Here, we assessed the potential association of sclerostin with the development of coronary artery (CAC) and aortic valve calcifications (AVC) in haemodialysis (HD) patients. METHODS: We conducted a cross-sectional multi-slice computed tomography (MS-CT) scanning study in 67 chronic HD patients (59.4 ± 14.8 yrs) for measurement of CAC and AVC. We tested established biomarkers as well as serum sclerostin (ELISA) regarding their association to the presence of calcification. Fifty-four adults without relevant renal disease served as controls for serum sclerostin levels. Additionally, sclerostin expression in explanted aortic valves from 15 dialysis patients was analysed ex vivo by immunohistochemistry and mRNA quantification (Qt-RT-PCR). RESULTS: CAC (Agatston score > 100) and any AVC were present in 65% and in 40% of the MS-CT patient group, respectively. Serum sclerostin levels (1.53 ± 0.81 vs 0.76 ± 0.31 ng/mL, p < 0.001) were significantly elevated in HD compared to controls and more so in HD patients with AVC versus those without AVC (1.78 ± 0.84 vs 1.35 ± 0.73 ng/mL, p = 0.02). Multivariable regression analysis for AVC revealed significant associations with higher serum sclerostin. Ex vivo analysis of uraemic calcified aortic valves (n = 10) revealed a strong sclerostin expression very close to calcified regions (no sclerostin staining in non-calcified valves). Correspondingly, we observed a highly significant upregulation of sclerostin mRNA in calcified valves compared to non-calcified control valves. CONCLUSION: We found a strong association of sclerostin with calcifying aortic heart valve disease in haemodialysis patients. Sclerostin is locally produced in aortic valve tissue adjacent to areas of calcification.

Functional cardiac MR imaging with true fast imaging with steady-state free precession before and after intravenous injection of contrast medium: comparison of image quality and accuracy.

OBJECTIVE: To compare image quality and accuracy of left ventricular function of cine SSFP (steady-state free precession) images before and after injection of Gd-DTPA. METHODS: In 30 patients T1 times of LV blood and myocardium were measured before and after injection of 0.2 mmol/kg body weight Gd-DTPA. Signal intensity of myocardium and left ventricular blood were measured on SSFP images and the contrast calculated. In 20 additional patients short axis images completely covering the left ventricle were acquired before and after injection of Gd-DTPA and parameters of left ventricular function compared. Image quality and regional function were assessed using the 17-segment model. RESULTS: Image quality after injection of contrast medium did not significantly change compared with unenhanced images. Contrast between myocardium and LV blood decreased from 0.6 ± 0.01 to 0.4 ± 0.03 after injection while the T1 value of myocardium decreased from 1121 ± 21 ms to 389 ± 14 ms (blood 1413 ± 48 ms to 222 ± 8 ms). Assessment of regional and global left ventricular function revealed similar results before and after the injection of contrast medium. CONCLUSION: Cine SSFP can be obtained after injection of contrast medium without loss of accuracy for regional and global LV ventricular function. This protocol can be used to decrease imaging time for thorough cardiac examination.

Electrocardiographic and imaging predictors for permanent pacemaker requirement after transcatheter aortic valve implantation.

BACKGROUND AND AIM OF THE STUDY: Pacemaker (PM) implantation is a possible requirement after transcatheter aortic valve implantation (TAVI). The study aim was to evaluate the electrocardiographic and imaging predictors of the need for PM implantation after TAVI. METHODS: A total of 80 consecutive patients (mean age 82 +/- 6 years) who had been referred for TAVI were included in the study. Transfemoral TAVI was performed in 58 patients (CoreValve ReValving; 72%), while 22 patients (28%) underwent transapical TAVI using the Edwards SAPIEN valve. Patient characteristics, and the frequency of atrioventricular (AV) block, right bundle branch block (RBBB) and left bundle branch block (LBBB), were evaluated for the prediction of PM implantation after TAVI. In addition, the severity and distribution of aortic valve calcification (AVC) were assessed by calculating the Agatston AVC score for the total aortic valve, as well as for each cusp, using dual-source computed tomography. RESULTS: Pre-procedural RBBB was present in six patients (8%), while eight patients (10%) showed pre-procedural LBBB. In 20 of the 80 patients (25%), a new LBBB was observed after TAVI. In 17 TAVI patients (21%; only CoreValve patients) there was an indication for permanent PM implantation that was related to complete AV block (n = 13) or complete RBBB or LBBB with AV delay (n = 4). Four of six patients (67%) with pre-procedural RBBB received a PM after TAVI. Multivariate logistic regression analysis revealed that only prosthesis type (r = 0.30, p = 0.01) and pre-procedural RBBB (r = 0.4, p = 0.02) were significantly associated with the need for permanent PM implantation after TAVI. CONCLUSION: TAVI is frequently associated with new conduction disturbances. A higher incidence of new LBBB and of permanent PM requirement occurred with the CoreValve ReValving system. There was no relationship between the severity or distribution of AVC and the need for PM implantation after TAVI. Patients with pre-procedural RBBB are deemed to be at risk for PM implantation after TAVI.

Aortic valve calcifications on chest films: how much calcium do I need?

OBJECTIVE: Aortic valve calcifications (AVC) as seen on conventional chest films or on CT are associated with aortic valve stenosis (AVS). The absence of AVC on chest films does not exclude high grade AVS. The aim of this study was to analyse if there is a threshold for the detection of AVC from conventional chest films in patients suffering from high grade AVS. METHODS AND RESULTS: The explanted aortic valves of 29 patients (16 male, mean age 72.3 +/- 11.5 years) with high grade AVS were examined by dual-source CT. AVC were quantified using the Agatston AVC score. In all patients conventional chest films obtained the day before surgery were evaluated for the presence of AVC. Results were analysed with students t-test, Spearman's rank correlation and ROC analysis. On conventional chest films AVC were visible in 18 patients. On CT all specimen presented with AVC with an Agatston AVC score ranging from 40.7 to 1870 (mean 991.3 +/- 463.1). In patients with AVC visible on chest films the AVC score was significantly higher (1264.0 +/- 318.2) when compared with patients without visible calcifications (544.9 +/- 274.4; P < 0.0001). There was a strong correlation between the AVC score and the visibility of AVC on chest films (r = 0.781). ROC analysis identified an ideal threshold of 718 for AVC score to separate conventional chest films with and without visible AVC. CONCLUSION: Unlike in coronary calcifications, there is a threshold for identifying AVC from conventional chest films. This finding may be of diagnostic value, as conventional chest films may be used to semiquantitatively evaluate the extent of AVC.

Association of fetuin-A levels with the progression of aortic valve calcification in non-dialyzed patients.

AIMS: Fetuin-A has been identified as a potent circulating inhibitor of ectopic calcification. We investigated the relationship between baseline fetuin-A serum levels and the rate of progression of aortic valve calcification (AVC) in non-dialyzed patients with aortic valve disease (AVD). METHODS AND RESULTS: Seventy-seven patients (mean age 70 +/- 8 years) with echocardiographically proven AVD were collected. In all patients, serum fetuin-A levels, creatinine, calcium, lipid parameters, and C-reactive protein were measured at baseline. For quantification of AVC progression, all patients underwent multislice spiral computed tomography examinations at baseline and after a mean follow-up of 12.6 +/- 1.4 months (range 7-18 months). In a multifactorial analysis of covariance including fetuin-A levels, baseline AVC score, the covariables sex, age, body mass index, C-reactive protein, glomerular filtration rate, serum lipids, diabetes, smoking status, and hypertension, only serum fetuin-A levels significantly predict the progression of AVC (P < 0.001). Post hoc analysis demonstrated that patients with baseline fetuin-A levels lower than the median of the cohort (0.72 g/L) showed a significantly higher increase of AVC scores (34.6 +/- 31.4%) than patients with fetuin-A levels larger than the median (10.0 +/- 11.2%, P < 0.001) despite comparable baseline AVC scores. In addition, fetuin-A levels were associated with major adverse clinical events (MACE; P = 0.03). CONCLUSION: Serum levels of the calcification inhibitor fetuin-A are associated with the progression of AVC and MACE, independent of the renal function and inflammation.

Relation of circulating Matrix Gla-Protein and anticoagulation status in patients with aortic valve calcification.

Matrix-Gla Protein (MGP) is a vitamin K-dependent protein acting as a local inhibitor of vascular calcification. Vitamin K-antagonists (oral anticoagulant; OAC) inhibit the activation of MGP by blocking vitamin K-metabolism. The aim of this study was to investigate the effect of long-term OAC treatment on circulating MGP levels in humans and on MGP expression in mice. Additionally, we tested the association between circulating inactive MGP (ucMGP) levels and the presence and severity of AVC in patients with aortic valve disease (AVD). We analysed circulating ucMGP levels in 191 consecutive patients with echocardiographically proven calcific AVD and 35 control subjects. The extent of AVC in the patients was assessed by multislice spiral computed tomography. Circulating ucMGP levels were significantly lower in patients with AVD (348.6 +/- 123.1 nM) compared to the control group (571.6 +/- 153.9 nM, p < 0.001). Testing the effect of coumarin in mice revealed that also the mRNA expression of MGP in the aorta was downregulated. Multifactorial analysis revealed a significant effect of glomerular filtration rate and long-term OAC therapy on circulating ucMGP levels in the patient group. Subsequently, patients on long-term OAC had significantly increased AVC scores. In conclusion, patients with calcific AVD had significantly lower levels of circulating ucMGP as compared to a reference population, free of coronary and valvular calcifications. In addition, our data suggest that OAC treatment may decrease local expression of MGP, resulting in decreased circulating MGP levels and subsequently increased aortic valve calcifications as an adverse side effect.

The circulating inactive form of matrix Gla Protein (ucMGP) as a biomarker for cardiovascular calcification.

OBJECTIVE: Matrix gamma-carboxyglutamate (Gla) protein (MGP) is a vitamin K-dependent protein and a strong inhibitor of vascular calcification. Vitamin K deficiency leads to inactive uncarboxylated MGP (ucMGP), which accumulates at sites of arterial calcification. We hypothesized that as a result of ucMGP deposition around arterial calcification, the circulating fraction of ucMGP is decreased. Here we report on the development of an ucMGP assay and the potential diagnostic utility of monitoring serum ucMGP levels. METHODS AND RESULTS: An ELISA-based assay was developed with which circulating ucMGP can be determined. Serum ucMGP levels were measured in healthy subjects (n = 165) and in four patient populations; patients who underwent angioplasty (n = 30), patients with aortic stenosis (n = 25), hemodialysis patients (n = 52), and calciphylaxis patients (n = 10). All four patient populations had significantly lower ucMGP levels. In angioplasty patients and in those with aortic stenosis, some overlap was observed with the control population. However, in the hemodialysis and calciphylaxis populations, virtually all subjects had ucMGP levels below the normal adult range. CONCLUSION: Serum ucMGP may be used as a biomarker to identify those at risk for developing vascular calcification. This assay may become an important tool in the diagnosis of cardiovascular calcification.

Feasibility and initial experience of assessment of mechanical dyssynchrony using cardiovascular magnetic resonance and semi-automatic border detection.

BACKGROUND: The systolic dyssynchrony index (SDI) has been introduced as a measure of mechanical dyssynchrony using three-dimensional echocardiography to select patients who may benefit from cardiac resynchronization therapy (CRT). However, three-dimensional echocardiography may be inadequate in a number of patients with suboptimal acoustic window and no single echocardiographic measure of dyssynchrony has proven to be of value in selecting patients for CRT. Thus, the aim of this study was to determine the value of cardiovascular magnetic resonance (CMR) for the assessment of the SDI in patients with reduced LV function as well as in healthy controls using semi-automatic border tracking. METHODS: We investigated a total of 45 patients including 35 patients (65 +/- 8 years) with reduced LV function (EF 30 +/- 11%) and a wide QRS complex as well as 10 control subjects (42 +/- 21 years, EF 70 +/- 11%). For cine imaging a standard SSFP imaging sequence was used with a temporal resolution of 40 frames per RR-interval. Quantitative analysis was performed off-line using a software prototype for semi-automatic border detection. Global volumes, ejection fraction and the SDI were calculated in each subject. SDI was compared with standard echocardiographic parameters of dyssynchrony. RESULTS: The mean SDI differed significantly between patients (14 +/- 5%) and controls (5 +/- 2%, p < 0.001). An exponential correlation between the EF and the SDI was observed (r = -0.84; p < 0.001). In addition, a significant association between the SDI and the standard deviation of time to peak systolic motion of 12 LV segments (Ts-SD) determined by echocardiography was observed (r = 0.66, p = 0.002). CONCLUSION: The results of this preliminary study suggest that CMR with semi-automatic border detection may be useful for the assessment of mechanical dyssynchrony in patients with reduced LV function.

Evaluation of aortocoronary bypass stents with cardiac MDCT compared with conventional catheter angiography.

OBJECTIVE: The objective of our study was to determine the accuracy of 16-MDCT for evaluation of stent patency and in-stent stenosis in venous coronary bypass grafts. SUBJECTS AND METHODS: Fourteen patients who had previous stent placements in stenosed venous coronary bypass grafts underwent contrast-enhanced MDCT of the heart (collimation, 16 x 0.75 mm; 120 kV; 550 mAs(eff)) and invasive coronary angiography. A total of 20 stents were evaluated: Vessel and stent diameters proximal to, distal to, and at various sites inside the stent were measured on both techniques, and Bland-Altman plots and correlations were calculated. Image noise and image quality were also assessed applying a Student's t test for data comparison of image noise. RESULTS: All 20 bypass stents were correctly classified as patent. Vessel diameters outside the stent showed an excellent correlation (r = 0.90) and in-stent diameters showed a good correlation (r = 0.72), with lower values for MDCT due to blooming artifacts. All significant in-stent stenoses were correctly classified. CONCLUSION: In patients suspected of bypass in-stent stenosis, 16-MDCT may be considered as a valuable alternative to conventional angiography for evaluating bypass patency and in-stent stenosis.

MDCT detection of mitral valve calcification: prevalence and clinical relevance compared with echocardiography.

OBJECTIVE: The purpose of this study was to analyze the prevalence and clinical significance of mitral valve calcification incidentally detected on chest CT scans in comparison with echocardiography. MATERIALS AND METHODS: The data of 390 patients (227 men and 163 women; mean age, 62.4 +/- 12.2 years) who underwent MDCT of the chest and echocardiography were retrospectively evaluated. On MDCT, mitral valve leaflet and annulus calcification were visually graded on a scale of 0-3, with grade 0 denoting no calcification and grade 3 indicating severe calcification. CT findings were correlated with hemodynamic data obtained at echocardiography. Unpaired Student's t tests, chi-square analysis, and a weighted-kappa test were used to compare results. RESULTS: In 32 (8.2%) of 390 patients, chest MDCT revealed mitral valve leaflet calcification. Fifteen of these patients (15/390, 3.8%) presented with mitral valve stenosis. Excellent agreement (kappa = 0.882) was seen between the presence of mitral valve calcification on MDCT and echocardiographically proven mitral valve sclerosis. Mitral valve leaflet calcification on MDCT and the severity of mitral valve disease on echocardiography showed a substantial agreement (kappa = 0.730). A significant relationship was seen between the degree of mitral valve calcification on MDCT and the echocardiographically determined severity of mitral valve disease (no sclerosis vs mitral sclerosis vs mitral stenosis; p < 0.0001). CONCLUSION: Mitral valve leaflet calcification on MDCT indicates mitral valve sclerosis or stenosis. Thus, patients presenting with incidentally detected mitral valve leaflet calcification on chest CT may benefit from a functional assessment with echocardiography.

Assessment of myocardial viability in reperfused acute myocardial infarction using 16-slice computed tomography in comparison to magnetic resonance imaging.

OBJECTIVES: The aim of this study was to examine if contrast-enhanced multislice spiral computed tomography (MSCT) is comparable to contrast-enhanced magnetic resonance imaging (MRI) for depiction of acute myocardial infarction (MI). BACKGROUND: Delayed-enhancement MRI of MI is well established, but there are no clinical reports about MSCT for this indication. Early perfusion deficit on MSCT has been reported to correlate with the presence of MI. METHODS: A total of 28 consecutive patients (23 men; 55.9 +/- 11.4 years) with reperfused MI underwent contrast-enhanced cardiac 16-slice MSCT. Images were acquired in the arterial phase and the late phase 15 min after administration of 120 ml contrast material. Within 5 days, patients underwent MRI after administration of 0.2 mmol Gd-dimeglumine/kg/bodyweight. All examinations were completed within two weeks after MI. The area of MI was compared between the different imaging techniques using Bland-Altman method and multivariate analysis. Agreement of the contrast enhancement patterns was evaluated with a weighted kappa test. RESULTS: Mean infarct size on MRI was 31.2 +/- 22.5% per slice compared with 33.3 +/- 23.8% per slice for late-enhancement MSCT and 24.5 +/- 18.3% per slice for early-perfusion-deficit MSCT. Bland-Altman data showed a good agreement between late-enhancement MRI and late-enhancement MSCT. Contrast enhancement patterns demonstrated an excellent agreement between late-enhancement MRI and late-enhancement MSCT (kappa = 0.878). The results were worse comparing MRI and early-phase MSCT (kappa = 0.635). CONCLUSIONS: Multislice spiral computed tomography allows for the assessment of acute MI. Late-enhancement MSCT appears to be as reliable as delayed contrast-enhanced MRI in assessing infarct size and myocardial viability in acute MI.

Quantification of aortic valve calcification using multislice spiral computed tomography: comparison with atomic absorption spectroscopy.

OBJECTIVES: Multislice spiral computed tomography (MSCT) allows the in vivo detection of valvular calcification. The aim of this study was to validate the quantification of aortic valve calcification (AVC) by MSCT with in vitro measurements by atomic absorption spectroscopy. METHODS: In 18 patients with severe aortic stenosis, 16 detector row MSCT (SOMATOM Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420 milliseconds tube rotation time, 12 x 0.75 mm collimation, tube voltage 120 KV) was performed before aortic valve replacement. Images were reconstructed at 60% of the RR interval with an effective slice thickness of 3 mm and a reconstruction increment of 2 mm. AVC was assessed using Agatston AVC score, mass AVC score, and volumetric AVC score. After valve replacement, the calcium content of the excised human stenotic aortic valves was determined in vitro using atomic absorption spectroscopy. RESULTS: The mean Agatston AVC score was 3,842 +/- 1,790, the mean volumetric AVC score was 3,061 +/- 1,406, and mass AVC score was 888 +/- 492 as quantified by MSCT. Atomic absorption spectroscopy showed a mean true calcification mass (Ca5(PO4)3OH) of 19 +/- 8 mass%. There was a significant correlation between in vivo AVC scores determined by MSCT and in vitro mean true calcification mass (r = 0.74, P = 0.0004 for mass AVC score, r = 0.79, P = 0.0001 for volumetric AVC score and r = 0.80, P = 0.0001 for Agatston AVC score) determined by atomic absorption spectroscopy. Linear regression analysis showed a significant association between the degree of hydroxyapatite (given in mass%) in the aortic valve and the degree of AVC (R = 0.74, F = 19.6, P = 0.0004 for mass AVC score, R = 0.80, F = 29.3, P = 0.0001 for Agatston AVC score and R = 0.79, F = 27.3, P = 0.0001 for volumetric AVC score) assessed by MSCT. CONCLUSION: MSCT allows accurate in vivo quantification of aortic valve calcifications.

Variability of aortic valve calcification measurement with multislice spiral computed tomography.

OBJECTIVES: We sought to assess the variability of aortic valve calcifications (AVCs) regarding the reconstruction window at different heart phases using multislice-spiral computed tomography. MATERIALS AND METHODS: A total of 46 patients (26 men; mean age. 65 years) underwent AVC scoring with multislice-spiral computed tomography (12 x 0.75 mm, 120 kV, 133 mAseff). Image reconstruction was performed every 10% of the RR-interval (0-90%). AVC was quantified using Agatston score, calcium volume, and calcium mass. Images were assessed for least motion artifacts. Coefficients of variation and Wilcoxon test were calculated. RESULTS: AVC scores are lowest at 60% and highest at 0% of the RR-interval (P < 0.001). Mean coefficients of variation were 36.2% (Agatston score), 38.7% (calcium volume), and 32.9% (calcium mass). At 60% (50-70%). minimal motion artifacts and the lowest variability of the scores were found. CONCLUSIONS: AVC scores show large variability depending on the point of image reconstruction. Diastolic image reconstruction at 60% of the RR-interval is recommended.

Multidetector-row computed tomography vs. angiography and intravascular ultrasound for the evaluation of the diameter of proximal coronary arteries.

BACKGROUND: Multidetector-row computed tomography has evolved as a promising method for noninvasive visualization of coronary arteries and detection of coronary artery calcification. We determined the accuracy of computed tomography for measurement of coronary artery lumen diameters in comparison to quantitative coronary angiography and intravascular ultrasound (IVUS). METHODS: Eighteen patients (4 female, age 62+/-8 years) with known or suspected coronary artery disease were investigated by computer tomography (4x1 mm collimation, rotation time: 500 ms, table feed: 1.5 mm/rotation). Coronary angiography and IVUS were performed in the left anterior descending, left circumflex and right coronary artery according to common standards. Lumen diameters were measured at the origin of the coronary artery and 10, 30 and 50 mm distally. Results of all three techniques were compared. RESULTS: Only measuring points evaluated by all measuring techniques were included. Thus, 50 diameters could be analyzed. The correlation R between computed tomography and angiography measures was 0.909 (p<0.05) at the origin of the artery, 0.907 (p<0.05) at 10, 0.841 (p<0.05) at 30 and 0.780 (p<0.05) at 50 mm distally. The correlation R between computed tomography and IVUS was 0.934 at the origin (p<0.05), 0.867 at 10 (p<0.05), 0.880 at 30 (p<0.05) and 0.727 at 50 mm (p<0.05). CONCLUSIONS: Multidetector-row computed tomography is a promising tool to measure the proximal coronary artery diameters with a good correlation to angiographic and IVUS measurements. Multidetector-row computed tomography might become more feasible with improvement of technology, e.g. with 16 row scanners.

Lower serum calcium levels are associated with greater calcium hydroxyapatite deposition in native aortic valves of male patients with severe calcific aortic stenosis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the relationship between serum calcium levels and the degree of calcification found in stenotic aortic valves. METHODS: Using atomic absorption spectroscopy, the hydroxyapatite content of 228 excised human stenotic aortic valves was determined and expressed as a percentage of valve mass. Left heart catheterization preceded valve replacement. In addition, serum levels of calcium and creatinine were determined before native calcific aortic valve excision. RESULTS: Valves from male patients contained more hydroxyapatite than those of female patients (26 +/- 9 versus 22 +/- 9 mass%; p < 0.001). Patients presenting with lower serum calcium levels showed a slight trend towards higher levels of valve calcification (r = -0.15, p = 0.026), but this association appeared only within the subgroup of male patients. Male patients with lowest serum calcium levels displayed greatest valvular hydroxyapatite deposition (1st calcium tertiary: 29.5 +/- 8.9 mass% versus 2nd calcium tertiary 26.4 +/- 7.8 mass% versus 3rd calcium tertiary 21.4 +/- 8.9 mass%; n = 122; p = 0.001; r = -0.25; p = 0.006). This association was even more distinct in male patients with normal serum creatinine levels. Furthermore, serum calcium was inversely and significantly associated with serum C-reactive protein in male patients (r = - 0.34; p < 0.001). CONCLUSION: Serum calcium levels appear to be inversely related to valve calcification in patients with severe calcific aortic stenosis (AS). This finding indicates the importance of systemic calcium metabolism in calcific AS, independent of manifest disorders of calcium metabolism or renal function. Interestingly, this association was evident only in male patients, suggesting a gender-dependent pathogenesis.

Multicentre evaluation of a rule-based data filter for home monitoring of implanted cardioverter defibrillators.

We developed a rule-based data filter for the automatic interpretation of data transmitted from implantable cardioverter defibrillators (ICDs). The feasibility and user acceptability of the data filter were tested in a multicentre study. Fifteen European centres analysed 10 cases each. The cases represented ICD follow-up findings, e.g. new tachycardia, battery depletion or sensing defects. The mean follow-up period was 68 days (SD 35). A questionnaire was used to collect information regarding the functionality and general concept of automatic data interpretation. A score of five or above (range 1-9) was classified as acceptable. According to the questionnaires, there was a high degree of satisfaction with the general concept of automatic data interpretation (mean 6.7, SD 1.2) and with user guidance (mean 7.1, SD 0.8). Safety (mean 7.0, SD 1.4) and accuracy (mean 6.7, SD 1.4) of the evaluation of device-related and clinical problems were regarded as high. Support in daily routine was considered to be high (mean 7.3, SD 1.1) as the system was easy to understand (mean 7.5, SD 0.9). The results indicated a high user acceptance with easy system handling.

Epicardial adipose tissue in long-term hemodialysis patients: its association with vascular calcification and long-term development.

BACKGROUND: Epicardial adipose tissue (EAT) is associated with coronary artery disease (CAD) in the general population. EAT is suggested to promote CAD by paracrine mechanisms and local inflammation. We evaluated whether in chronic hemodialysis (HD) patients EAT associates with CAD, how the amount of EAT develops over time, and if EAT independently predicts the mortality risk. METHODS: Post-hoc analysis of a prospective study in 59 chronic HD patients who underwent non-enhanced multi-slice computed tomography (MSCT) at baseline. Thirty-seven patients underwent another MSCT after 24 ± 5 months. We measured EAT volume (cm³) and Agatston calcification scores of coronary arteries (CAC) and aortic valves (AVC). All-cause mortality was assessed after a follow-up of 88 months (IQR 52-105). RESULTS: Baseline EAT was 128.2 ± 60.8 cm³ and significantly higher than in a control group of non-renal patients (94 ± 46 cm³; p < 0.05). Median Agatston score for CAC was 329 (IQR 23-1181) and for AVC was 0 (IQR 0-25.3) in HD patients. We observed significant positive correlations between baseline EAT and age (r = 0.386; p = 0.003), BMI (r = 0.314; p = 0.016), CAC (r = 0.278; p = 0.03), and AVC (r = 0.282; p = 0.03). In multivariate analysis, age, BMI and AVC remained as significant predictors of EAT (p < 0.01). Calcification scores significantly increased over 2 years; in contrast EAT change was not significant (+11 %, IQR -10 to 24 %; p = 0.066). The limited patient number in the present study precludes analysis of the EAT impact upon survival. CONCLUSION: EAT correlated significantly with cardiovascular calcification in long-term HD patients. Mean EAT did not significantly change over 2 years.